With 40 fresh cases of dengue in the national capital, the number of patients suffering from the viral disease rose to 997 on Tuesday. One person succumbed to the disease at the AIIMS Monday evening, taking the total number of deaths in Delhi to 23.

"Forty new cases of dengue were reported in the capital since Monday," Delhi Health Secretary D S Negi said. Of the 40 fresh cases, 34 were admitted to the AIIMS, where 173 people undergoing treatment for the disease.

Thirty four people, including Prime Minister Manmohan Singh's son-in-law Vijay Tankha, have been discharged in the past 24 hours, officials said. This year, the number of dengue cases have registered a nearly a three-fold increase compared to the corresponding period last year when it had affected nearly 300.

Sprucing up its dengue-control measures, the Delhi government Monday issued instructions for closing down all water fountains, including those at Rajpath and in residential premises.

"We have asked the authorities to ensure that water is drained out from all the fountains," Negi said adding that the municipal corporation's zonal deputy commissioners were asked to coordinate the activities of sanitation and malaria control to ensure cleanliness in the city.

AIIMS, which has the maximum number of patients afflicted by the disease, has also augmented its facilities by drafting additional doctors and creating a new emergency ward for dengue.